Controllable synthesis of perovskite-like PbBiO2Cl hollow microspheres with enhanced photocatalytic activity for antibiotic removal

Novel perovskite-like PbBiO2Cl materials with hollow and porous sphere-like structures were successfully synthesized using a polyvinyl pyrrolidone (PVP) and reactive ionic liquid 1-hexadecyl-3-methylimidazolium chlorine ([C(16)mim] Cl) complex system. TEM was employed to characterize the hollow-porous structure formed by the double regulation of the ionic liquid and PVP. The achieved hollow-porous PbBiO2Cl sphere-like photocatalyst showed excellent photocatalytic activity towards the degradation of the colorless antibiotic agents ciprofloxacin (CIP) and tetracycline (TC) under visible light irradiation. The enhanced photocatalytic performance of the PbBiO2Cl materials was mainly derived from the porous and hollow structure, which enables a larger specific surface area and faster interfacial charge separation. Moreover, based on the analysis of XPS valence spectra, electron spin resonance (ESR) spectra and free radical trapping experiments, the main active species were determined to be holes and superoxide radicals during the photocatalytic degradation process. According to the results of the characterizations and the comparative tests, possible growth and photocatalytic reaction mechanisms were proposed.